FR2751253A1 - METHOD AND PLANT FOR MACHINING A BALL CAGE OF A CV JOINT AND BALL CAGE OBTAINED BY THIS METHOD - Google Patents

Abstract

The invention relates to a method of machining a ball cage (10) of a constant velocity transmission joint, in which a piece is cut from a tube, the outer and inner faces of the piece are successively formed for their give the shape of a sphere, we realize in the plot lights (11) retaining the balls, we carry out a heat treatment of the ball cage (10) and we perform a finishing machining of the outer sphere and the inner sphere. The ball retaining slots (11) are produced by cutting the piece by means of an electron beam with high energy density. The invention also relates to an installation for machining a ball cage of a constant velocity transmission joint for motor vehicles.

Description

The subject of the present invention is a method and an installation

machining a ball cage of a

  constant velocity joint.

  The present invention also relates to

  a ball cage of a constant velocity transmission joint

than achieved by this process.

  CV joints

  are intended to connect two shafts of a motor vehicle

  mobile, namely a transverse motor half-shaft and a

rous rocket.

  Conventionally, this seal essentially comprises an external bell-shaped element integral with the rocket and an internal element adapted to be fixed on the motor half-shaft by means, for example,

splines and a circlip.

  The interior and exterior elements are mounted one inside the other by means of a ball cage comprising lights for retaining said balls. These balls cooperate with grooves formed, on the one hand, in the cavity of the external element and, on the other hand, on the peripheral surface of the internal element. Up to now, this type of ball cage has been produced by cutting a piece from a tube, then, by forming, on the one hand, the external face of the piece to give it the shape of a sphere and, on the other hand, from the inside of said piece to also give it the

shape of a sphere.

  Then, the ball retaining lights are produced by punching the slug and a

  heat treatment of the ball cage.

  Finally, a finishing machining of the outer sphere and the inner sphere of said one is carried out.

ball cage.

  However, the formation of ball retaining lights by punching has drawbacks. In constant velocity joints, the torque transmission is ensured by the balls guided in the cage windows and the breaking strength of these joints is essentially determined by the breaking strength

of said cage.

  Indeed, the punching generates in the cage deformations which can destroy the geometrical conditions to obtain and decrease the resistance to the rupture of this cage, because this punching can cause

primers of rupture.

  In addition, the roughness resulting from the punching of the ball holding lights is most often

  causing cases of breakages of homogeneous seals

  kinetics. In addition, the lights produced by

  punching all have the same dimensions adapted

  tees to allow disassembly of the inner element

from the cage.

  Finally, the realization of the lights by poin-

  Sealing requires a different set of punches depending on the dimensions of the cage and the lights to be obtained. These punches must be regularly remanufactured taking into account the constraints they undergo at the time

punching.

  The object of the invention is to avoid these inconveniences.

  nients by proposing a method and an installation for machining ball joints of constant velocity joints having a great flexibility of machining and making it possible to optimize the shape of the lights as well as to obtain a

high machining precision.

  The subject of the invention is therefore a method of machining a ball cage of a constant velocity transmission joint, method in which: - a piece is cut from a tube, - the external face of the piece is formed to give it the shape of a sphere, - we form the inside face of the piece to give it the shape of a sphere, - we realize in the piece of ball retaining lights, - and we carry out a heat treatment of the ball cage , - a finishing machining of the outer sphere and the inner sphere is carried out, characterized in that ball-retaining lights are produced by cutting the piece by means of a

  electron beam with high energy density.

  The invention also relates to an installation for machining a ball cage of a constant velocity transmission joint, of the type comprising: - means for cutting a piece of material in a tube, - means for forming the outside face of the piece to give it the shape of a sphere, -means for forming the inside face of the piece to give it the shape of a sphere, - means for machining in the piece of ball retaining lights , - means for heat treatment of the ball cage, - and means for finishing the outer sphere and the inner sphere, characterized in that the means for machining the ball retaining slots are formed, on the one hand, by a table movable transversely and provided with at least one horizontal pin for supporting a ball cage and 4_ movable in rotation and, on the other hand, at least one nozzle for cutting the lights by beam d high energy density electrons above said

  spindle and vertically movable.

  According to other characteristics of the invention: the table comprises two horizontal and parallel spindles each supporting a ball cage, the installation comprises two cutting nozzles using a high density electron beam

  of energy, each arranged above a spindle.

  The invention also relates to a cage of a constant velocity transmission joint comprising ball retaining lights, characterized in that

  that it is carried out by the process mentioned above.

  The ball cage according to the invention can

  have one or more of the following characteristics:

  tes: - the side faces of the lights converge towards the center of said cage, - one of the lights has dimensions

superior to other lights.

  Other features and benefits of

  the invention will appear during the description which

  will follow, made with reference to the accompanying drawings, in which: - Figure 1 is a schematic view in

  cross section of a constant velocity joint

  that provided with a ball cage produced by the method according to the invention, Figure 2 is a perspective view

  a ball cage obtained by the process according to the inv-

ention,

  - Figure 3 is a cross-sectional view

  dirty ball cage, - Figure 4 is a schematic elevational view of the means for machining the lights in the ball cage, - Figure 5 is a schematic side view of the means for machining the lights in the cage ball.

  In Figure 1, there is shown schematically

  only a constant velocity transmission joint designated as a whole by the reference 1 and intended to connect

  two shafts of a motor vehicle, namely a half

  transverse motor shaft 2 and a wheel spindle 3.

  This constant velocity joint 1 essentially comprises

  tial an external element 4 in the form of a bell formed integrally with the rocket 3 and an internal element adapted to be fixed on the motor half-shaft 2 to the

  by means of grooves 6 and a circlip 7.

  The exterior and interior elements,

  pectively 4 and 5, are mounted one inside the other by

  through a ball cage 10.

  As shown in Figure 2, the cage 10 is formed by a portion of tube having an outer surface in the form of a sphere and a surface

  interior also in the shape of a sphere.

  This cage 10 also includes lights 1il uniformly distributed around the periphery of said cage

  which are intended to retain balls 8, as re-

shown in Figure 1.

  The balls 8 cooperate with grooves, not shown, formed, on the one hand, in the cavity of the external element 4 and, on the other hand, on the surface

  inner element peripheral 5.

  In the embodiment shown in FIGS. 2 and 3, the openings 11 are six in number, respectively 11a, 11b ... llf, each comprising two longitudinal faces, respectively 12 and 13, and

  two side faces, respectively 14 and 15.

  As shown in Figure 3, the side faces 14 and 15 of the lights lia, llb ... llf converge

  all towards the center of the ball cage 10.

  Furthermore, one of the lights 11 for example-

  ple the light lia has dimensions larger than the other lights 1lb ... llf so that it can be mounted

  the inner element 5 of said ball cage 10.

  The method of machining the ball cage 10 consists of cutting a piece 9 from a tube, successively forming the outside face of the piece 9 to give it the shape of a sphere and the inside face of said piece to also give it the shape of a sphere and to make in the plot the lights 11 for retaining

balls 8.

  Then, the method consists in carrying out a

  heat treatment of ball cage 10 and to effect

  kill a finish machining of the outer sphere and

  of the inner sphere of said ball cage 10.

  According to the invention, the holes 11 for retaining the balls 8 of the ball cage 10 are produced by cutting by means of a high-electron beam.

energy density.

  For this, the installation for machining the ball cage 10 comprises means for cutting a piece from a tube, means for successively forming the outside face and the inside face of each piece to give them the form of a sphere and machining means in said lumines 9 of light 11 of

ball retention 8.

  This installation also includes means for heat treatment of the ball cage 10

  and means for finishing machining of the outer sphere

  the inner sphere of said ball cage 10. In FIGS. 4 and 5, only machining means have been shown in the billet 9 of the

  lights 11 for retaining the balls 8.

  These machining means are formed by an assembly designated by the reference 20 which comprises a frame 21, the upper surface of which is provided with a table 22 which can be moved transversely by means of slides 23 and a conventional system 24, for example.

  consisting of a nut and worm gear assembly.

  Table 22 supports two spindles 25 parallel

  leles intended to each receive a piece 9 intended for

  each form a ball cage 10.

  As shown in Figure 5, each spindle 25 is rotated for example by a

motor-reducer assembly 26.

  The means of machining the lights 11 comprises

  are also trying two nozzles 27 for cutting the lights 11 in the plots 9 by high electron beam

energy density.

  As shown in Figure 4, each nozzle 27 is disposed above a pin 25 and is

  mounted at the end of a vertically movable column 28

  securely by appropriate means 29.

  As shown in Figure 4, the installation

  tion comprises means 30 for feeding the pieces 9 on the pins 25 and means 40 for discharging the

  ball cages 10 after machining the lights 11.

  The feed means 30 are constituted for example by a feed tube 31, an elevator 32 and a loading arm 33 simultaneously of two

plots 9 on pins 25.

  This loading arm 33 is pivotally mounted about a horizontal axis 34 and has at its end

  free two gripping organs of the pieces 9.

  The means 40 for evacuating the cages 10 are formed by an unloading arm 41 mounted pivoting about a horizontal axis 42 and which comprises, at its

  free end, two gripping members for the cages 10.

  The means of evacuating the cages 10 comprises

  also try a discharge tube 43.

  5.The means of machining the lights 11 of

  ball cages 10 operate in the following manner.

  After cutting the pieces 9 from a tube and forming the outer and inner faces of said pieces 9, these pieces are poured into the loading tube 31, then transported by the elevator 32 to the arm of

loading 33.

  The loading arm 33 after gripping two pieces 9 pivots about the axis 34 between a vertical position and a horizontal position so that these pieces 9 are in the axis of the

pins 25.

  Then, by moving the table 22, the two pieces 9 are transferred to the pins 25 and the loading arm 33 is returned to its position

vertical.

  The nozzles 25 are lowered at a determined distance from the pieces 9 and by transverse displacement of the table 22 and rotation of the pins 25, each light 11 is produced successively on the two pieces 9 by means of two electron beams with high density of energy. The transverse displacement of the table 22 as well as the rotation of the spindles 25 are programmed in

  depending on the dimensions of the lights to be produced.

  After machining the lights 11, the arm of

  unloading 41 pivots to position itself horizontal-

  ment and the ball cages 10 are transferred from the pins 25 to the gripping members of the unloading arm 41 and this unloading arm pivots to be brought into a vertical position and the cages to

  balls 10 are discharged through the discharge tube 43.

  The cycle starts again for machining two

other plots and so on.

  The machining of the lights 11 of the ball cages 10 by electron beam with high energy density has the advantage of being able to optimize the shape of the lights as well as to obtain high precision and

great flexibility of machining.

  Furthermore, the method and the installation according to the invention having the advantage of being able to machine

  lights at the right dimensions which allows

  put material and remove any deformation during the machining of these lights, while maintaining the geometric conditions of the ball cage after

the machining of these lights.

Claims (7)

RESELL I CATIONS   1. Method for machining a ball cage (10) of a constant velocity transmission joint (1), method in which: - a piece (9) is cut from a tube, - the outside face of the piece is formed (9) to give it the shape of a sphere, - the inner face of the piece is formed (9) to give it the shape of a sphere, - lights (11) are retained in the piece (9) balls (8), - and a heat treatment of the ball cage (10) is carried out, - a finishing machining of the external sphere and the internal sphere is carried out, characterized in that the lights are produced ( 11) retaining the balls (8) by cutting the piece (9) at   using a high density electron beam gie.   2. Installation for machining a ball cage (10) of a constant velocity transmission joint (1), of the type comprising: - means for cutting a piece (9) in a tube, - means for forming the outside face of the piece (9) to give it the shape of a sphere, - means for forming the inside face of the piece (9) to give it the shape of a sphere, - machining means in the plot (9) of lights (11) for retaining the balls (8), - means for heat treatment of the ball cage (10), - and means for machining the outer sphere and the inner sphere, characterized in that the means for machining the lights (11) for retaining the balls (8) are formed, on the one hand, by a table (22) movable transversely and provided with at least one horizontal spindle ( 25) for supporting a ball cage (10) which can be moved in rotation and, on the other hand, by at least one nozzle (27) for cutting the lights (11) by electron beam s with high energy density, disposed above said pin (25) and vertically movable.   3. Installation according to claim 2, characterized in that the table (22) comprises two pins (25) horizontal and parallel supporting each a ball cage (10).   4. Installation according to claims 1 and   2, characterized in that it comprises two nozzles (27) for cutting by high density electron beam   each arranged above a spindle (25).   5. Ball cage (10) of a transmission joint   constant velocity sion (1), comprising lights (11) for retaining the balls (8), characterized in that it is   carried out by the method according to claim 1.   6. Ball cage according to claim 5,   characterized in that the lateral faces (14,15) of the slots (11) converge towards the center of said cage ball (10).   7. Ball cage according to claims 5   and 6, characterized in that one of the lights (11a) has dimensions greater than the other lights (11).